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<Title>ChartViewer.addViewPortListener</Title>
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<p class="heading0">ChartDirector 7.0 (Java Edition)</p>
<p class="heading1"><a href="ChartViewer.htm">ChartViewer</a>.<wbr>addViewPortListener</p>
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<p class="heading2a">Usage</p>
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public void addViewPortListener(ViewPortListener listener)
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<p class="heading2">Description</p>
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Adds the specified <a href="ViewPortListener.htm">ViewPortListener</a> to receive viewport events.<br><br>
Currently, viewport events include the "viewport changed" event and the "selection changed" event. The "viewport changed" event occurs when the viewport is changed by mouse actions (see <a href="ChartViewer.setMouseUsage.htm">ChartViewer.setMouseUsage</a>), or <a href="ChartViewer.updateViewPort.htm">ChartViewer.updateViewPort</a> is called. The "selection changed" event occurs when the selection box is changed (becomes visible or invisible or change in size) by "drag to select" mouse actions.
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<p class="heading2">Arguments</p>
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<th width="19%">Argument</th><th width="19%">Default</th><th>Description</th>
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<td>listener</td><td>(Mandatory)</td><td>The <a href="ViewPortListener.htm">ViewPortListener</a> object to receive viewport events.</td>
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<p class="heading2">Return Value</p>
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None
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